I have never thought of Shamir's Secret Shares as being for anything other than multipath message relaying, combined with AONT, and would need Reed Solomon to prevent the need for resending, and for creating N of M paper recovery keys for HD wallets and similar identity systems.

It just doesn't make sense with multiple online storage locations. You can't give strong guarantee of trust with that without first protecting anonymity of the user. For backup, you just want QR bitmaps protected by keys, share them to your friends for backup and the cipher via a back channel.

There's a lot that could be done to improve that use case.

I think we are very early when it comes to making understanding of how to secure data with reduction of single points of failure. I don't think that best practices are even really established.